The Medici were among the most powerful families in the world. Beginning in the fourteenth century, they built a fortune bankrolling popes and kings. Through their wealth and their political abilities, they went from being one of many patrician clans in Florence to the city's hereditary rulers. They married into the royal houses of Austria and France, and two of their number were made pope. Scholars and lovers of art, the Medici were patrons of Leonardo, Raphael, Botticelli, Galileo, Michelangelo, and Cellini. And under their rule, Florence became the intellectual hub of the Western world.

The Medici were also legendary for their adeptness at intrigue and murder. In 1537, for example, Cosimo I came to power when the reigning duke, Alessandro Medici, was assassinated by a cousin. The 18-year-old Cosimo--son of Giovanni Medici, the family's greatest military captain, but from a junior branch--was not accepted by many of the leading families of Florence. They took up arms against him, but Cosimo was victorious on the battlefield. And those of his opponents who survived, including Alessandro's murderer, met with "unfortunate accidents" shortly thereafter.

Many of the leading Medici were buried in the Chapel of San Lorenzo in Florence, which long enjoyed the family's patronage. In 2004, we obtained Superintendent Antonio Paolucci's permission to examine 47 of the Medici interred there, including Cosimo. The multiyear project is a unique opportunity to study the health of the Medici (a rare look at a single family over a long period) and might settle allegations of murder to be found in legends about the dynasty.

We had no idea what we would find. In 1857, after it was discovered that the Medici tombs, then above ground in the chapel, had been plundered, their remains were buried below its floor for protection. Brass plaques set into the floor indicate where they were buried, but there were no precise records of how they were buried. Moreover, in 1947 researchers intent primarily on examining the skulls exhumed several Medici but left virtually no record of what they found or how they reburied them. A final uncertainty was what effect the disastrous 1966 flood of the Arno River, which inundated the chapel, might have had on the remains.

Gino Fornaciari is professor of the history of medicine and pathology at the University of Pisa. Bob Brier is senior research fellow at the C.W. Post Campus of Long Island University and a contributing editor of ARCHAEOLOGY. Antonio Fornaciari is an archaeologist with the Medici project.